Quantum spin liquids (QSLs) represent a state where a local moment system remains non-ordered at zero temperature due to geometrical or quantum frustrations. The Barlowite Cu4(OH)6FBr with TN = 15 K has been suggested to be a good candidate to obtain the QSL state if the inter-site Cu can be replaced by Zn. Recently, we have successfully synthesized Cu3.08Zn0.92(OH)6FBr without showing magnetic order down to 50 mK. More interestingly, we found that only low-energy spin excitations change with Zn content level, suggesting a gapped QSL in Cu3.08Zn0.92(OH)6FBr. However, there is no report on the spin excitations of barlowite, which must be our first step to understand the Cu4-xZnx(OH)6FBr system. We thus propose to study the low-energy spin excitations in barlowite.